Combination wind/solar dc power system

ABSTRACT

A direct current power system. The direct current power system includes a direct current bus system, a solar power system, an energy storage system and a wind power system. The solar power system is configured to supply a first direct current power. The energy storage system has an input electrically coupled to the solar power system and is configured to supply a second direct current power at 380 volts to the direct current bus system. The wind power system includes is electrically coupled to the energy storage system and is configured to supply a third direct current power.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §120 of the earlierfiling date of United States Patent Application Number 15/433,302 filedon Feb. 15, 2017, which claims the benefit under 35 U.S.C. § 119(e) ofthe earlier filing date of U.S. Provisional Pat. Application No.62/295,349 filed on Feb. 15, 2016, the entire contents of each which arehereby incorporated by reference.

BACKGROUND

This application discloses an invention which is related, generally andin various aspects, to a combination wind/solar DC power system.

Currently, a significant amount of the electrical power generated byutility companies utilize nonrenewable sources of energy (e.g., coal,petroleum, natural gas) to generate the electrical power. For a varietyof reasons, many people throughout the world believe it would be prudentto wean away from nonrenewable sources of energy and utilize renewablesources of energy (e.g., solar, wind, etc.) to generate electricalpower.

The electrical power generated by utility companies is generated asalternating current (AC) power and subsequently transmitted over atransmission grid and a distribution grid to end users. In homes,commercial buildings and industrial facilities, the AC power istypically distributed throughout the electrical distribution system ofthe home/building/facility as AC power. However, since there are manytypes of electrical equipment (appliances, computers, data centers,light-emitting diode lighting fixtures, etc.) in thehomes/buildings/facilities which require direct current (DC) power toproperly operate, the AC power has to be converted to DC power for suchelectrical equipment, and the required conversion results in substantialpower loss and wasted energy.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the aspects described herein are set forth withparticularity in the appended claims. The aspects, however, both as toorganization and methods of operation may be better understood byreference to the following description, taken in conjunction with theaccompanying drawings.

FIG. 1 illustrates a simplified representation of a DC power systemaccording to various aspects;

FIG. 2 illustrates a simplified representation of a solar power systemof the DC power system of FIG. 1 according to various aspects;

FIG. 3 illustrates a solar power system of the DC power system of FIG. 1according to other aspects;

FIG. 4 illustrates various aspects of a wind power system of the DCpower system of FIG. 1 ;

FIG. 5 illustrates various aspects of a battery stack of the wind powersystem of FIG. 4 ;

FIG. 6 illustrates various aspects of a rectifier system of the DC powersystem of FIG. 1 ;

FIG. 7 illustrates various aspects of an energy storage system of the DCpower system of FIG. 1 ;

FIG. 8 illustrates various aspects of a battery stack of the energystorage system of FIG. 7 ;

FIG. 9 illustrates the energy storage system of FIG. 7 according toother aspects; and

FIG. 10 illustrates various aspects of an inverter system of the DCpower system of FIG. 1 .

DETAILED DESCRIPTION

It is to be understood that at least some of the figures anddescriptions of the invention have been simplified to illustrateelements that are relevant for a clear understanding of the invention,while eliminating, for purposes of clarity, other elements that those ofordinary skill in the art will appreciate may also comprise a portion ofthe invention. However, because such elements are well known in the art,and because they do not facilitate a better understanding of theinvention, a description of such elements is not provided herein.

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols and reference characters typically identify similarcomponents throughout several views, unless context dictates otherwise.The illustrative aspects described in the detailed description, drawingsand claims are not meant to be limiting. Other aspects may be utilized,and other changes may be made, without departing from the scope of thetechnology described herein.

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, aspects, embodiments, examples, etc. described herein maybe combined with any one or more of the other teachings, expressions,aspects, embodiments, examples, etc. that are described herein. Thefollowing described teachings, expressions, aspects, embodiments,examples, etc. should therefore not be viewed in isolation relative toeach other. Various suitable ways in which the teachings herein may becombined will be readily apparent to those of ordinary skill in the artin view of the teachings herein. Such modifications and variations areintended to be included within the scope of the claims.

Before explaining the various aspects of the DC power system in detail,it should be noted that the various aspects disclosed herein are notlimited in their application or use to the details of construction andarrangement of parts illustrated in the accompanying drawings anddescription. Rather, the disclosed aspects may be positioned orincorporated in other aspects, variations and modifications thereof, andmay be practiced or carried out in various ways. Accordingly, aspects ofthe DC power system disclosed herein are illustrative in nature and arenot meant to limit the scope or application thereof. Furthermore, unlessotherwise indicated, the terms and expressions employed herein have beenchosen for the purpose of describing the aspects for the convenience ofthe reader and are not meant to limit the scope thereof. In addition, itshould be understood that any one or more of the disclosed aspects,expressions of aspects, and/or examples thereof, can be combined withany one or more of the other disclosed aspects, expressions of aspects,and/or examples thereof, without limitation.

Also, in the following description, it is to be understood that termssuch as outward, inward, above and the like are words of convenience andare not to be construed as limiting terms. Terminology used herein isnot meant to be limiting insofar as devices described herein, orportions thereof, may be attached or utilized in other orientations. Thevarious aspects will be described in more detail with reference to thedrawings.

FIG. 1 illustrates a simplified representation of a direct current (DC)power system 10 according to various aspects. The DC power system 10includes a DC bus system 12, a solar power system 14, a wind powersystem 16 and an energy storage system 18. According to various aspects,the DC power system 10 also includes a rectifier system 20 and/or aninverter system 22.

The DC power system 10 may be utilized to provide DC power to a DC load24 electrically coupled to the DC power system 10. For purposes ofsimplicity, the DC power system 10 will be described hereinafter in thecontext of being configured to provide 380 volts of DC power to the DCload 24. However, it will be appreciated that the DC power system 10 maybe configured to provide DC voltages other than 380VDC to the DC load24. For aspects which include the inverter system 22, the DC powersystem 10 may also be configured to provide alternating current (AC)power to an AC load 26 electrically coupled to the DC power system 10.

Although only one DC load 24 is shown in FIG. 1 as being electricallycoupled to the DC power system 10, it will be appreciated that anynumber of DC loads may be electrically coupled to the DC power system10. Similarly, although only one AC load 26 is shown in FIG. 1 as beingelectrically coupled to the DC power system 10, it will be appreciatedthat any number of AC loads may be electrically coupled to the DC powersystem 10.

Although not shown for purposes of clarity in FIG. 1 , it will beappreciated that the DC bus system 12 includes a first conductor and asecond conductor. In general, the first conductor is positively chargedrelative to the second conductor. Thus, the first conductor mayconsidered as the +V_(DC) conductor of the DC bus system 12 and thesecond conductor may be considered as the -V_(DC) conductor of the DCbus system 12. Although the electrical connections to the DC bus system12 are shown in FIG. 1 as single line connections, it will beappreciated that sub-systems of the DC power system 10 which areconnected to the DC bus system 12 each have two electrical connectionsto the DC bus system 12 - one to the +V_(DC) conductor and one to the-V_(DC) conductor.

According to various aspects, the DC bus system 12 is configured tocarry 380VDC of DC power. According to other aspects, the DC bus system12 is configured to carry more than or less than 380VDC of DC power.According to various aspects, the configuration and functionality of theDC bus system 12 is similar or identical to the StarLine B250 Amp Buswaymanufactured by Universal Electric Corporation.

The DC load 24 is electrically coupled to the DC bus system 12 via anappropriately sized circuit breaker and/or disconnect switch (notshown). The DC load 24 may be any suitable type of DC load. For example,according to various aspects, the DC load 24 is a data center whichincludes components (e.g., servers) which require 380 volts of DC powerto properly operate. According to other aspects, the DC load 24 is alighting load (e.g., LED lighting fixtures) or other load which require380 volts of DC power to properly operate.

The DC power system 10 may also be utilized with DC loads 24 whichrequire more than or less than 380VDC. For aspects where the DC load 24requires more than 380VDC, the DC power system 10 may further include aDC-DC converter (not shown) which boosts the 380VDC provided by the DCbus system 12 to a DC voltage suitable for the DC load 24. For aspectswhere the DC load 24 requires less than 380VDC, the DC power system 10may further include a DC-DC converter (not shown) which reduces the380VDC provided by the DC bus system 12 to a DC voltage suitable for theDC load 24.

FIG. 2 illustrates a simplified representation of the solar power system14 according to various aspects. The solar power system 14 iselectrically coupled to the energy storage system 18 via anappropriately sized circuit breaker and/or disconnect switch (not shown)and includes a plurality of solar panels 28 and a photovoltaic chargecontroller 30.

The solar panels 28 may be any suitable type of solar panel. Forexample, according to various aspects the configuration andfunctionality of the solar panels 28 are similar or identical to theSunmodule Plus SW 280 Mono solar panels manufactured by SolarWorld.Although the plurality of solar panels 28 are shown as a single block inFIG. 2 for purposes of simplicity, it will be appreciated that the solarpower system 14 may include any number of solar panels 28 and the solarpanels 28 may be arranged in any suitable manner. For example, accordingto various aspects the solar power system 14 is a 50 kilowatt systemwhich includes one-hundred eighty high-efficiency monocrystallinephotovoltaic solar panels 28 arranged into six arrays of thirty solarpanels 28 each (or twelve arrays of fifteen solar panels 28 each), whereeach solar panel 28 nominally generates 280 watts of power at 31.2volts.

The output side of the plurality of solar panels 28 are electricallycoupled to the photovoltaic charge controller 30 via the appropriatelysized circuit breaker and/or disconnect switch (not shown), and theoutput side of the photovoltaic charge controller 30 is coupled to aninput side of the energy storage system 18. The photovoltaic chargecontroller 30 may be any suitable type of charge controller. Thephotovoltaic charge controller 30 is configured to boost the nominalvoltage generated by the solar panels 28 to a voltage suitable for theenergy storage system 18 (e.g., 48VDC). For example, the photovoltaiccharge controller 30 may boost the output voltage of the plurality ofsolar panels 28 to a DC voltage which is slightly over the existingvoltage of the energy storage system 18 and then maintain a voltagehigher than the voltage of the energy storage system 18 in order to“push” current from the solar power system 14 to the energy storagesystem 18. According to various aspects, the photovoltaic chargecontroller 30 also includes internal controls which prevents thephotovoltaic charge controller 30 from “pushing” too much current fromthe solar power system 14 to the energy storage system 18.

FIG. 3 illustrates the solar power system 14 according to other aspects.For these aspects, in lieu of being coupled to the energy storage system18 as described above with reference to FIG. 2 , the solar power system14 is coupled to the DC bus system 12 via an appropriately sized circuitbreaker and/or disconnect switch (not shown) and includes a plurality ofsolar panels 28 and a plurality of DC-DC converters 32. According tovarious aspects, the solar power system 14 also includes acommunications unit 34.

The solar panels 28 may be similar or identical to those described abovewith reference to FIG. 2 . Although the solar power system 14 is shownin FIG. 3 as including thirty-six solar panels 28, arranged in sixarrays, it will be appreciated that the solar power system 14 mayinclude any number of solar panels 28 and the solar panels 28 may bearranged into any number of arrays. For example, according to variousaspects, the solar power system 14 is a 50 kilowatt system whichincludes one-hundred eighty high-efficiency monocrystalline photovoltaicsolar panels 28 arranged into three arrays of sixty solar panels 28 each(or six arrays of six solar panels 28 each), where each solar panel 28nominally generates 280 watts of power at 31.2 volts.

The DC-DC converters 32 are configured to boost the nominal voltagegenerated by the individual solar panels 28. The solar system 14 mayinclude any number of DC-DC converters 32. For example, as shown in FIG.3 , according to various aspects, the solar power system 14 includes oneDC-DC converter 32 for every two solar panels 28, wherein each DC-DCconverter 32 is electrically connected to the outputs of two of thesolar panels 28. The DC-DC converters 32 are electrically coupled to oneanother in parallel and are configured to collectively boost the outputvoltage of the plurality of solar panels 28 to a DC voltage suitable forthe DC bus system 12. For example, according to various aspects, theDC-DC converters 32 are configured to collectively boost the outputvoltage from the plurality of solar panels 28 to 380VDC. According tovarious aspects, the DC-DC converters 32 may also serve as chargecontrollers for the solar power system 14 by boosting the output voltageof the plurality of solar panels 28 to a DC voltage which is slightlyover the existing voltage of the DC bus system 12 and then maintaining avoltage higher than the voltage of the DC bus system 12 in order to“push” current from the solar power system 14 to the DC bus system 12.According to various aspects, the DC-DC converters 32 also includeinternal controls which prevent the DC-DC converters from “pushing” toomuch current from the solar power system 14 to the DC bus system 12.According to various aspects, if the energy storage system 18 is fullycharged and there is no load electrically coupled to the DC bus system12, the DC-DC converters 32 may be deactivated. The DC-DC converters 32may be any suitable type of DC-DC boost converters. According to variousaspects, the configuration and functionality of the DC-DC converters 32are similar or identical to the vBoost 600 DC-to-DC converter modulesmanufactured by eIQ Energy, Inc.

For aspects which do not include the communications unit 34, one of theDC-DC converters 32 from each array of solar panels 28 may beelectrically coupled to the DC bus system 12 via an appropriately sizedcircuit breaker and/or disconnect switch (not shown). For aspects whichdo include the communications unit 34, the communications unit 34 iselectrically coupled to a plurality of the DC-DC converters 32 (coupledto one DC-DC converter 32 for each array of solar panels 28), and isalso electrically coupled to the DC bus system 12 via an appropriatelysized circuit breaker and/or disconnect switch (not shown). According tovarious aspects, if the energy storage system 18 is fully charged andthere is no load electrically coupled to the DC bus system 12, thecommunications unit 34 may sense this condition and operate todeactivate the DC-DC converters 32. According to various aspects, thecommunications unit 34 is configured to monitor the performance of thesolar panels 28 and DC-DC converters 32, and to communicate performanceinformation regarding the solar panels 28 and the DC-DC converters 32 toan energy monitoring system (not shown). The energy monitoring system isconfigured to process the performance information and present theinformation in a manner which is suitable for understanding theperformance of and/or troubleshooting the solar power system 14.According to various aspects, the configuration and functionality of thecommunications unit 34 is similar or identical to the Vcomm modulemanufactured by eIQ Energy, Inc.

FIG. 4 illustrates various aspects of the wind power system 16. The windpower system 16 is electrically coupled to the DC bus system 12 via anappropriately sized circuit breaker and/or disconnect switch (not shown)and includes a wind turbine assembly 36, a charge controller 38, anenergy storage system 40 and a DC-DC converter 42. According to variousaspects, the wind power system 16 also includes an inverter 44.

Although the wind power system 16 is shown in FIG. 4 as including asingle wind turbine assembly 36, it will be appreciated that the windpower system 16 may include any number of wind turbine assemblies 36.According to various aspects, the wind power system 16 is a 5 kilowattsystem which includes one portable, vertical axis wind turbine (notshown) which includes a plurality of vertically-oriented blades, agenerator mechanically coupled to the blades and a rectifierelectrically coupled to the generator. For such aspects, rotation of theblades produces rotation of the generator, resulting in the generationof AC power. The rectifier converts the AC power to DC power at a DCvoltage suitable for the energy storage system 40 (e.g., 48VDC). Thewind turbine assembly 36 may be any suitable type of wind turbineassembly. According to various aspects, the configuration andfunctionality of the wind turbine assembly 36 is similar or identical tothe Windstax 40 wind turbine manufactured by WindStax Wind PowerSystems.

The energy storage system 40 is configured to store the DC powerproduced by the wind turbine assembly 36 and includes a plurality ofbattery stacks 46 which each have a plurality of batteries 48 (See FIG.5 ) connected to one another either in series or in parallel. Althoughthe energy storage system 40 is shown in FIG. 4 as having four batterystacks 46, it will be appreciated that the energy storage system 40 mayinclude any number of battery stacks 46, with each battery stack 46including any number of batteries 48. According to various aspects, theenergy storage system 40 is a 9.6 kilowatt-hour energy storage systemwhich includes four battery stacks 46, where each battery stack 46includes eight batteries 48 (See FIG. 5 ) which can collectivelystore/deliver 2.4 kilowatt-hours of energy at 48VDC. According to otheraspects, the energy storage system 40 is a 12.0 kilowatt-hour energystorage system which includes five battery stacks 46, where each batterystack 46 includes eight batteries 48 (See FIG. 5 ) which cancollectively store/deliver 2.4 kilowatt-hours of energy at 48VDC. Thebatteries 48 of the battery stacks 46 may be any suitable type ofbatteries. For example, according to various aspects, the batteries 48include a saltwater electrolyte, a manganese oxide cathode, a carboncomposite anode and a synthetic cotton separator, and utilizenon-corrosive reactions at the anode and cathode to preventdeterioration of the materials. According to various aspects, theconfiguration and functionality of the battery stacks 46 of the energystorage system 40 are similar or identical to the S20-P008F BatteryStacks manufactured by Aquion Energy. Additionally, according to variousembodiments, the direct current power system 10 may further includesensors (not shown) which are utilized to monitor the temperature of thebattery stacks 46 and/or the batteries 48.

The charge controller 38 is electrically coupled to the wind turbineassembly 36 and the energy storage system 40, and is configured tomaintain the charge on the batteries 48 of the energy storage system 40.The charge controller 38 may be any suitable type of charge controller.According to various aspects, the configuration and functionality of thecharge controller 38 is similar or identical to the MS4448PAE InverterCharger manufactured by Magnum-Dimensions. According to various aspects,the charge controller 38 may also be electrically coupled, via anappropriately sized circuit breaker and/or disconnect switch (notshown), to an AC power system (not shown). For such aspects, the chargecontroller 38 may utilize a feed from the AC power system to rechargethe batteries 48 as needed.

The DC-DC converter 42 is electrically coupled to the energy storagesystem 40 and is configured to boost the 48VDC output from the energystorage system 40 to a DC voltage suitable for the DC bus system 12. Forexample, according to various aspects, the DC-DC converter 42 isconfigured to boost the 48VDC output voltage from the energy storagesystem 40 to 380VDC. According to various aspects, the DC-DC converter42 may also serve as a charge controller for the wind power system 16 byboosting the output voltage of the energy storage system 40 to a DCvoltage which is slightly over the existing voltage of the DC bus system12 and then maintaining a voltage higher than the voltage of the DC bussystem 12 in order to “push” current from the wind power system 16 tothe DC bus system 12. According to various aspects, the DC-DC converter42 also includes internal controls which prevent the DC-DC converter 42from “pushing” too much current from the wind power system 16 to the DCbus system 12. According to various aspects, the DC-DC converter 42 mayprovide DC power to the DC bus system 12 as long as the battery stacks46 of the energy storage system 40 remain above a predetermined chargelevel. If the battery stacks 46 drop below the predetermined chargelevel (e.g., if the voltage drops below 2.5 VDC for any battery 48), theDC-DC converter 42 may stop providing DC power to the DC bus system 12until the battery stacks 46 are recharged by the wind turbine assembly36. According to various aspects, if the energy storage system 18 isfully charged and there is no load electrically coupled to the DC bussystem 12, the DC-DC converter 42 may be deactivated. The DC-DCconverter 42 may be any suitable type of DC-DC boost converter.According to various aspects, the configuration and functionality of theDC-DC converter 42 is similar or identical to the Flatpack 2 DC/DCConverter manufactured by Eltek.

The inverter 44 is electrically coupled to the charge controller 38 andto one or more AC circuits (not shown). The inverter 44 is configured toreceive DC power from the charge controller 38 and convert the DC powerto AC power, which may then be provided to the one or more AC circuits.The inverter 44 may be any suitable type of inverter. According tovarious aspects, the configuration and functionality of the inverter 44is similar or identical to the MS4448PAE Inverter Charger manufacturedby Magnum-Dimensions.

FIG. 6 illustrates various aspects of the rectifier system 20. Therectifier system 20 includes a rectifier 50 which is electricallycoupled to an AC power system 52 via an appropriately sized circuitbreaker and/or disconnect switch (not shown) and is also electricallycoupled to the DC bus system 12 via an appropriately sized circuitbreaker and/or disconnect switch (not shown). The AC power provided bythe AC power system 52 may be generated in any suitable manner. Forexample, the AC power may be generated by one or more hydroelectricpower plants, coal-fired power plants, oil-fired power plants, naturalgas-fueled power plants, nuclear power plants, etc.

The rectifier 50 is configured to convert the AC power from the AC powersystem 52 to DC power at a DC voltage suitable for the DC bus system 12.According to various aspects, the rectifier system 20 is a 30 kilowattrectifier system which is configured to convert 480VAC, 3-phase AC powerfrom the AC power system 52 to 380VDC. For instances where solar powersystem 14, the wind power system 16 and/or the energy storage system 18are unable to provide sufficient DC power to satisfy one or more loadsconnected to the DC bus system 12, the rectifier system 20 may providethe necessary amount of DC power to the DC bus system 12 to satisfy theloads. According to various aspects, the rectifier system 20 includesadvanced functionality such as, for example, intelligent control,metering, monitoring and distribution. For example, the rectifier 50 mayinclude internal controls which prevent the rectifier 50 from “pushing”too much current from the rectifier system 20 to the DC bus system 12.The rectifier system 20 may be configured to operate either with orwithout batteries. The rectifier 50 may be any suitable type ofrectifier. According to various aspects, the configuration andfunctionality of the rectifier 50 is similar or identical to the NetSure4015 DC Power System manufactured by Emerson Network Power. As shown inFIG. 6 , according to various aspects, the AC power system 52 may alsoprovide AC power to the AC load 26.

FIG. 7 illustrates various aspects of the energy storage system 18. Theinput side of the energy storage system 18 is coupled to the solar powersystem 14 (See FIG. 2 ) and the output side of the energy storage system18 is electrically coupled to the DC bus system 12. For purposes ofsimplicity, the electrical connections to the input side of the energystorage system 18 are not shown in FIG. 7 . For these aspects, theenergy storage system 18 is configured to be charged by the DC powerproduced by the solar power system 14, to store DC power, and dischargethe DC power stored by the energy storage system 18 to the DC load 24and/or the inverter system 22 via the DC bus system 12.

The energy storage system 18 includes a plurality of battery stacks 54which each have a plurality of batteries 56 (See FIG. 8 ) connected toone another either in series or in parallel. By connecting a pluralityof the nominal 48VDC battery stacks in series, the energy storage system18 can provide 380VDC of DC power to the DC bus system 12. Although theenergy storage system 18 is shown in FIG. 7 as having five batterystacks 54, it will be appreciated that the energy storage system 18 mayinclude any number of battery stacks 54, with each battery stack 54including any number of batteries 56. According to various aspects, theenergy storage system 18 includes five battery stacks 54, where eachbattery stack 54 includes eight batteries 56 which can collectivelydeliver 15 kilowatt-hours of energy at 380VDC to the DC bus system 12.For such aspects, the batteries 56 are lithium iron phosphate (LiFePO₄)batteries, the configuration and functionality of the battery stacks 54are similar or identical to the 15KWH modular LFP Energy Banksmanufactured by Elecyr Corporation and the energy storage system 18 candeliver 75 kilowatt-hours of energy at 380VDC.

According to other aspects, the energy storage system 18 includesthirty-two battery stacks 54, where each battery stack 54 includes eightbatteries 56 which can collectively deliver 2 kilowatt-hours of energyat 380VDC to the DC bus system 12. For such aspects, the batteries 56are saltwater batteries (they include a saltwater electrolyte, amanganese oxide cathode, a carbon composite anode and a synthetic cottonseparator, and utilize non-corrosive reactions at the anode and cathodeto prevent deterioration of the materials), the configuration andfunctionality of the battery stacks 54 are similar or identical to theS30-0800 battery stack manufactured by Aquion Energy and the energystorage system 18 can deliver 64 kilowatt-hours of energy at 380VDC tothe DC bus system 12.

The output side of each battery stack 54 is electrically coupled to theDC bus system 12 via an appropriately sized circuit breaker and/ordisconnect switch (not shown). According to various aspects, the batterystacks 54 include controls which prevent the batteries 56 from becomingovercharged and prevent the batteries 56 from “pushing” too much currentto the DC bus system 12. According to various aspects, the energystorage system 18 may provide DC power to the DC bus system 12 as longas the battery stacks 54 of the energy storage system 18 remain above apredetermined charge level. If the battery stacks 54 drop below thepredetermined charge level (e.g., if the voltage drops below 2.5 VDC forany battery 56), the energy storage system 18 may stop providing DCpower to the DC bus system 12 until the battery stacks 54 are rechargedby the solar power system 14. Additionally, according to variousembodiments, the direct current power system 10 may further includesensors (not shown) which are utilized to monitor the temperature of thebattery stacks 54 and/or the batteries 56.

For the above-described aspects, it will be appreciated that duringnormal operation, (1) the energy storage system 18, which is charged bythe solar power system 14, is configured to deliver the majority of thedirect current power to the DC load 24 and/or the AC load 26 via thedirect current bus system 12 and (2) the direct current power generatedby the wind power system 16 and delivered to the direct current bussystem 12 supplements the direct current power delivered to the directcurrent bus 12 by the energy storage system 18.

According to other aspects, the input side of the energy storage system18 is electrically coupled to the -V_(DC) conductor of the DC bus system12 and the output side of the energy storage system 18 is electricallycoupled to the +V_(DC) conductor of the DC bus system 12 (See FIG. 9 ).For such aspects, the batteries 56 of the energy storage system 18 maybe charged with DC power supplied by the solar power system 14, the windpower system 16 and/or the rectifier system 20.

FIG. 9 illustrates the energy storage system 18 according to otheraspects. For the aspects shown in FIG. 9 , each battery stack 54 may beelectrically coupled to the DC bus system 12 via a pair of chargecontrollers 58, 60 and appropriately sized circuit breakers and/ordisconnect switches (not shown). For purposes of simplicity, only one ofthe charge controllers 58 and one of the charge controllers 60 are shownin FIG. 9 . The charge controllers 58 control current flowing from theDC bus system 12 to the battery stacks 54 (i.e., charging controllers)and the charge controllers 60 control current flowing from the batterystacks 54 to the DC bus system 12 (i.e., discharging controllers). The“charging” charge controllers 58 include circuitry (not shown) whichoperates to allow DC power to only flow in one direction from the DC bussystem 12 to the battery stacks 54 and the “discharging” chargecontrollers 60 include circuitry (not shown) which operates to allow DCpower to only flow in one direction from the battery stacks 54 to the DCbus system 12. According to various aspects, each “charging” chargecontroller 58 also includes bypass circuitry (not shown) which operatesto limit the DC current flowing from the DC bus system 12 to the batterystack 54 to a nominal minimum for slow charging the batteries 56.According to various aspects, each “discharging” charge controller 60also includes bypass circuitry (not shown) which operates to limit theDC current flowing from the battery stacks 54 to the DC bus system 12 toa nominal minimum for pre-charging (or soft-starting) the DC bus system12. As separate connections are utilized to connect a given batterystack 54 to the +V_(DC) conductor and the -V_(DC) conductor of the DCbus system 12, it will be appreciated that the energy storage system 18can independently control its charging and discharging. According tovarious aspects, all of the DC power provided by the solar power system14, the wind power system 16 and/or the inverter system 20 may beprovided to charge the battery stacks 54 of the energy storage system18, and the energy storage system 18 may provide all of the DC power tothe loads connected to the DC bus system 12.

FIG. 10 illustrates various aspects of the inverter system 22. Theinverter system 22 includes an inverter 62, is electrically coupled tothe DC bus system 12 via an appropriately sized circuit breaker and/ordisconnect switch (not shown), and is also electrically coupled to theAC load 26 via an appropriately sized circuit breaker and/or disconnectswitch (not shown). The inverter 62 is configured to convert the DCpower from the DC bus system 12 to AC power at an AC voltage suitablefor the AC load 26. Such suitable AC voltages may include, for example,120VAC, 208VAC, 240VAC, 277VAC and/or 480VAC. According to variousaspects, the inverter system 22 is a 40 kilowatt inverter system whichis configured to convert 380VDC to 480VAC for utilization by the AC load26. The AC load 26 may be any suitable type of AC load. For example,according to various aspects, the AC load 26 is a lighting circuit whichrequires 277 volts of single-phase AC power to properly operate.According to other aspects, the AC load 26 is an air conditioning unitwhich requires 480 volts of three-phase AC power to properly operate.For applications where the DC power system 10 is to provide AC power toAC loads 26 having different AC voltage requirements, the invertersystem 22 may include additional inverters 62 to convert the DC powerfrom the DC bus system 12 to AC power at the AC voltages suitable forthe different AC loads 26.

According to various aspects, the inverter 62 includes a digital signalprocessor (DSP) which utilizes pulse width modulation (PWM) to controlinsulated-gate bipolar transistors (IGBT) to convert the DC power fromthe DC bus system 12 to AC power at an AC voltage suitable for the ACload 26. The inverter 62 may be any suitable type of inverter. Accordingto various aspects, the configuration and functionality of the inverter62 is similar or identical to a 40KVA Power Inverter manufactured byPower Conversion Technologies, Inc.

As shown in FIG. 10 , according to various aspects, the inverter system22 may further include an automatic transfer switch 64 electricallycoupled to the inverter 62 and positioned between the inverter 62 andthe above-referenced appropriately sized circuit breaker and/ordisconnect switch (not shown) electrically coupled to the AC load 26.The automatic transfer switch 64 may also be electrically coupled to theAC power system 52. The automatic transfer switch 64 is configured toallow AC power from either the AC power system 52 or the inverter system22/inverter 62 to be electrically connected to the AC load 26. Accordingto various aspects, during normal operation, the automatic transferswitch 64 connects the inverter 62 to the AC load 26 and allows the ACpower to flow from the output side of the inverter 62 to the AC load 26.During such operation, the automatic transfer switch 64 effectivelydisconnects the AC power system 52 from the AC load 26. However, if theDC power system 10 fails or if the AC power from the inverter 62 is notsufficient to meet the AC load 26, the automatic transfer switch 64 mayautomatically disconnect the inverter 62 from the AC load 26 and connectthe AC power system 52 to the AC load 26.

Examples

Example 1 - A direct current power system is provided. The directcurrent power system comprises a direct current bus system, a solarpower system, an energy storage system, a wind power system, a rectifiersystem and an inverter system. The solar power system comprises aplurality of solar panels, wherein the solar power system is configuredto supply a first direct current power at 48 volts. The energy storagesystem is electrically coupled to the solar power system and the directcurrent bus system, wherein the energy storage system comprises aplurality of battery stacks, and wherein the energy storage system isconfigured to supply a second direct current power at 380 volts to thedirect current bus system. The wind power system is electrically coupledto the direct current bus system, wherein the wind power systemcomprises at least one wind turbine assembly, and wherein the wind powersystem is configured to supply a third direct current power at 380 voltsto the direct current bus system. The rectifier system is electricallycoupled to an alternating current power system and the direct currentbus system, wherein the rectifier system is configured to supply afourth direct current power at 380 volts to the direct current bussystem. The inverter system is electrically coupled to the directcurrent bus system and electrically couplable to an alternating currentload.

Example 2 -The direct current power system of Example 1, wherein thesolar power system further comprises a photovoltaic charge controllerelectrically coupled to the plurality of plurality of solar panels andthe energy storage system.

Example 3 - The direct current power system of Example 1, wherein thesolar power system further comprises a plurality of DC-DC converterselectrically coupled to the plurality of solar panels.

Example 4 - The direct current power system of Examples 1, 2 or 3,wherein each battery stack comprises a plurality of batteries.

Example 5 - The direct current power system of Example 4, wherein the atleast one of the battery stacks comprises a plurality of saltwaterbatteries.

Example 6 - The direct current power system of Examples 1, 3, 4 or 5,wherein the energy storage system further comprises (1) a firstplurality of charge controllers electrically coupled to the energystorage system and a positively charged conductor of the DC bus systemand (2) a second plurality of charge controllers electrically coupled tothe energy storage system and a negatively charged conductor of the DCbus system.

Example 7 - The direct current power system of Examples 1, 2, 3, 4, 5 or6, wherein the at least one turbine assembly comprises a vertical axisturbine assembly.

Example 8 - The direct current power system of Examples 1, 2, 3, 4, 5, 6or 7, wherein the wind power system further comprises (1) a chargecontroller electrically coupled to the at least one wind turbineassembly, (2) an energy storage subsystem electrically coupled to thecharge controller and (3) a DC-DC converter electrically coupled to theenergy storage subsystem and the direct current bus system.

Example 9 - The direct current power system of Example 8, wherein theenergy storage subsystem comprises a plurality of battery stacks.

Example 10 - The direct current power system of Example 9, wherein eachbattery stack comprises a plurality of batteries.

Example 11 - The direct current power system of Examples 9 or 10,wherein at least one of the battery stacks comprises a plurality ofsaltwater batteries.

Example 12 - The direct current power system of Examples 8, 9, 10 or 11,wherein the wind power system further comprises an inverter electricallycoupled to the charge controller.

Example 13 - The direct current power system of Examples 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 11 or 12, wherein the rectifier system comprises arectifier configured to convert alternating current power from thealternating current power system to the fourth direct current power.

Example 14 - The direct current power system of Examples 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 11, 12 or 13, wherein the inverter system comprises aninverter configured to convert direct current power from the directcurrent bus system to alternating current power.

Example 15 - The direct current power system of Example 14, wherein theinverter system further comprises an automatic transfer switchelectrically coupled to the inverter, the alternating current powersystem and the alternating current load.

Example 16 - A direct current power system is provided. The directcurrent power system comprises a solar power system, a wind powersystem, an energy storage system, a rectifier system and a 380 voltdirect current bus system. The solar power system comprises a pluralityof solar panels, wherein the solar power system is configured to outputa first direct current power. The wind power system comprises at leastone wind turbine assembly, wherein the wind power system is configuredto output a second direct current power. The energy storage systemcomprises a plurality of battery stacks, wherein the energy storagesystem is electrically coupled to the solar power system and isconfigured to output a third direct current power. The rectifier systemis configured to supply a fourth direct current power. The 380 voltdirect current bus system is electrically coupled to the wind powersystem, the energy storage system and the rectifier system.

Example 17 - The direct current power system of Example 16, wherein thesolar power system further comprises a communications unit configured to(1) monitor performance of the solar power system and (2) communicateperformance information regarding the solar power systems.

Example 18 - The direct current power system of Examples 16 or 17,further comprising an inverter system electrically coupled to the 380volt direct current bus system.

Example 19 - A direct current power system is provided. The directcurrent power system comprises a 380 volt direct current bus system, asolar power system, means for storing energy, a wind power system and arectifier system. The solar power system comprises a plurality of solarpanels, wherein the solar power system is configured to generate a firstdirect current power. The means for storing energy is electricallycoupled to the solar power system and is configured to supply a seconddirect current power to the 380 volt direct current bus system. The windpower system is configured to supply a third direct current power to the380 volt direct current bus system. The rectifier system is configuredto supply a fourth direct current power to the 380 volt direct currentbus system.

Example 20 - The direct current power system of Example 19, furthercomprising an inverter system electrically coupled to the 380 voltdirect current bus system.

Although various aspects have been described herein, many modifications,variations, substitutions, changes and equivalents to those aspects maybe implemented and will occur to those skilled in the art. For example,although the solar power system 14 and the wind power system 16 weredescribed in the context of being able to operate in conjunction with anAC power system 52, it will be appreciated that the solar power system14, the wind power system 16, the energy storage system 18 and the DCbus system 12 may be able to operate in conjunction with any number ofrenewable and/or non-renewable energy sources. The solar power system14, the wind power system 16, the energy storage system 18 and the DCbus system 12 may be able to operate in conjunction with any number ofdifferent AC power systems (e.g., hydroelectric, coal-fired, oil-fired,natural gas-fueled, nuclear, etc.) and/or any number of other sources ofDC power.

Additionally, although exemplary “capacities” have been described inconnection with various components of the direct current power system 10(50KW solar power system, 5KW wind power system, 64-75KW energy storagesystem, 30KW rectifier, etc.), it will be appreciated that according toother aspects of the direct current power system 10 the respectivecapacities can vary, sometimes significantly. For example, based on thegeographic location of the direct current power system 10, theparameters of the weather generally associated with the geographiclocation, the number of DC loads 24 to be powered by the direct currentpower system 10, the amount of power which needs to be delivered to theDC load(s) 24, the number of AC loads 26 to be powered by the directcurrent power system 10, the amount of power which needs to be deliveredto the AC load(s) 26, etc., the capacities of the various components ofthe direct current power system 10 can be tailored to best meet theneeds of a given application. For example, for some applications, thewind power system 16 may supply a higher percentage of or even amajority of the direct current power delivered to the direct current bussystem 12.

Also, where materials are disclosed for certain components, othermaterials may be used. It is therefore understood that the foregoingdescription and the appended claims are intended to cover all suchmodifications and variations as falling within the scope of thedisclosed aspects. The following claims are intended to cover all suchmodifications and variations.

While this invention has been described as having exemplary designs, thedescribed invention may be further modified within the spirit and scopeof the disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples.

1-20. (canceled)
 21. A direct current power system, comprising: a directcurrent bus system; a solar power system configured to supply a firstdirect current power; an energy storage system comprising: an inputelectrically coupled to the solar power system and detached from thedirect current bus system; and an output electrically coupled to thedirect current bus system, wherein the energy storage system isconfigured to supply a second direct current power to the direct currentbus system; and a wind power system electrically coupled to the directcurrent bus system, wherein the wind power system is configured tosupply a third direct current power.
 22. The direct current power systemof claim 1, wherein the solar power system comprises a plurality ofsolar panels.
 23. The direct current power system of claim 1, whereinthe energy storage system comprises a plurality of batteries.
 24. Thedirect current power system of claim 3, wherein at least one of theplurality of batteries comprises lithium.
 25. The direct current powersystem of claim 3, wherein at least one of the plurality of batteriescomprises saltwater.
 26. The direct current power system of claim 1,wherein the wind power system comprises at least one wind turbineassembly.
 27. The direct current power system of claim 6, wherein the atleast one wind turbine assembly comprises a vertical axis wind turbineassembly.
 28. The direct current power system of claim 1, wherein thewind power system further comprises at least one AC-DC converter. 29.The direct current power system of claim 1, further comprising a DC-DCcharge controller electrically coupled to the solar power system and theenergy storage system.
 30. The direct current power system of claim 9,further comprising a second DC-DC charge controller electrically coupledto the energy storage system and the direct current bus system.
 31. Thedirect current power system of claim 1, further comprising a rectifiersystem electrically coupled to an alternating current power system andthe direct current bus system, wherein the rectifier system isconfigured to supply a fourth direct current power.
 32. The directcurrent power system of claim 11, wherein the rectifier system comprisesa rectifier configured to convert alternating current power from thealternating current power system to the fourth direct current power. 33.The direct current power system of claim 1, further comprising aninverter system electrically coupled to the direct current bus systemand electrically couplable to an alternating current load.
 34. Thedirect current power system of claim 13, wherein the inverter systemcomprises an inverter configured to convert direct current power fromthe direct current bus system to alternating current power.
 35. A directcurrent power system, comprising: a solar power system configured tooutput a first direct current power; a wind power system configured tooutput a second direct current power; an energy storage systemcomprising an input electrically coupled to the solar power system,wherein the energy storage system is configured to output a third directcurrent power; a direct current bus system electrically coupled to thewind power system and the energy storage system, wherein the input ofthe energy storage system is detached from the direct current bussystem; and a converter configured to convert an output of the directcurrent bus system to an input suitable for a load coupled to the directcurrent bus system.
 36. The direct current power system of claim 15,wherein the energy storage system comprises a plurality of batteries,wherein at least one of the plurality of batteries comprises at leastone of the following: lithium; and saltwater.
 37. The direct currentpower system of claim 15, further comprising a DC-DC charge controllerelectrically coupled to the solar power system and the energy storagesystem.
 38. The direct current power system of claim 17, furthercomprising a second DC-DC charge controller electrically coupled to theenergy storage system and the direct current bus system.
 39. The directcurrent power system of claim 15, further comprising at least one of thefollowing: a rectifier system configured to supply a fourth directcurrent power; and an inverter system electrically coupled to the directcurrent bus system.
 40. A direct current power system, comprising: adirect current bus system; a solar power system configured to generate afirst direct current power; a means for storing energy, wherein themeans for storing energy: comprises an input electrically coupled to thesolar power system and detached from the direct current bus system; andis configured to supply a second direct current power to the directcurrent bus system; and a wind power system comprising at least one windturbine assembly, wherein the wind power system is configured to supplya third direct current power and is electrically coupled to the directcurrent bus system.